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https://github.com/DanteAlighierin/foot

Unofficial Mirror: A fast, lightweight and minimalistic Wayland terminal emulator
https://github.com/DanteAlighierin/foot

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Unofficial Mirror: A fast, lightweight and minimalistic Wayland terminal emulator

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# ![Logo: a terminal with a foot shaped prompt](icons/hicolor/48x48/apps/foot.png) foot



The fast, lightweight and minimalistic Wayland terminal emulator.



[![CI status](https://ci.codeberg.org/api/badges/dnkl/foot/status.svg)](https://ci.codeberg.org/dnkl/foot)

[![Pipeline status](https://gitlab.com/dnkl/foot/badges/master/pipeline.svg)](https://gitlab.com/dnkl/foot/commits/master)

[![builds.sr.ht status](https://builds.sr.ht/~dnkl/foot.svg)](https://builds.sr.ht/~dnkl/foot?)



[![Packaging status](https://repology.org/badge/vertical-allrepos/foot.svg)](https://repology.org/project/foot/versions)



## Index



1. [Features](#features)

1. [Installing](#installing)

1. [Configuration](#configuration)

1. [Troubleshooting](#troubleshooting)

1. [Why the name 'foot'?](#why-the-name-foot)

1. [Fonts](#fonts)

1. [Shortcuts](#shortcuts)

   1. [Keyboard](#keyboard)

      1. [Normal mode](#normal-mode)

      1. [Scrollback search](#scrollback-search)

   1. [Mouse](#mouse)

   1. [Touchscreen](#touchscreen)

1. [Server (daemon) mode](#server-daemon-mode)

1. [URLs](#urls)

1. [Shell integration](#shell-integration)

   1. [Current working directory](#current-working-directory)

   1. [Jumping between prompts](#jumping-between-prompts)

   1. [Piping last command's output](#piping-last-command-s-output)

1. [Alt/meta](#alt-meta)

1. [Backspace](#backspace)

1. [Keypad](#keypad)

1. [DPI and font size](#dpi-and-font-size)

1. [Supported OSCs](#supported-oscs)

1. [Programmatically checking if running in foot](#programmatically-checking-if-running-in-foot)

1. [XTGETTCAP](#xtgettcap)

1. [Credits](#Credits)

1. [Bugs](#bugs)

1. [Contact](#contact)

   1. [IRC](#irc)

   1. [Mastodon](#mastodon)

1. [Sponsoring/donations](#sponsoring-donations)

1. [License](#license)



## Features



* Fast (see [benchmarks](doc/benchmark.md), and

  [performance](https://codeberg.org/dnkl/foot/wiki/Performance))

* Lightweight, in dependencies, on-disk and in-memory

* Wayland native

* DE agnostic

* Server/daemon mode

* User configurable font fallback

* On-the-fly font resize

* On-the-fly DPI font size adjustment

* Scrollback search

* Keyboard driven URL detection

* Color emoji support

* IME (via `text-input-v3`)

* Multi-seat

* True Color (24bpp)

* [Synchronized Updates](https://gitlab.freedesktop.org/terminal-wg/specifications/-/merge_requests/2) support

* [Sixel image support](https://en.wikipedia.org/wiki/Sixel)



  ![wow](doc/sixel-wow.png "Sixel screenshot")



# Installing



See [INSTALL.md](INSTALL.md).



## Configuration



**foot** can be configured by creating a file

`$XDG_CONFIG_HOME/foot/foot.ini` (defaulting to

`~/.config/foot/foot.ini`).  A template for that can usually be found

in `/etc/xdg/foot/foot.ini` or

[here](https://codeberg.org/dnkl/foot/src/branch/master/foot.ini).



Further information can be found in foot's man page `foot.ini(5)`.



## Troubleshooting



See the [wiki](https://codeberg.org/dnkl/foot/wiki#user-content-troubleshooting)



## Why the name 'foot'?



I'm bad at names. Most of my projects usually start out as _foo

something_ (for example, [yambar](https://codeberg.org/dnkl/yambar)

was _f00bar_ for a while).



So why _foot_?



_foo terminal_ → _footerm_ → _foot_



Pretty bad, I know.



As a side note, if you pronounce the _foo_ part of _foot_ the same way

you pronounce _foobar_, then _foot_ sounds a lot like the Swedish word

_fot_, which incidentally means (you guessed it) _foot_.



## Fonts



**foot** supports all fonts that can be loaded by _freetype_,

including **bitmap** fonts and **color emoji** fonts.



Foot uses _fontconfig_ to locate and configure the font(s) to

use. Since fontconfig's fallback mechanism is imperfect, especially

for monospace fonts (it doesn't prefer monospace fonts even though the

requested font is one), foot allows you, the user, to configure the

fallback fonts to use.



This also means you can configure _each_ fallback font individually;

you want _that_ fallback font to use _this_ size, and you want that

_other_ fallback font to be _italic_?  No problem!



If a glyph cannot be found in _any_ of the user configured fallback

fonts, _then_ fontconfig's list is used.



## Shortcuts



These are the default shortcuts. See `man foot.ini` and the example

`foot.ini` to see how these can be changed.



### Keyboard



#### Normal mode



shift+page up/page down

: Scroll up/down in history



ctrl+shift+c, XF86Copy

: Copy selected text to the _clipboard_



ctrl+shift+v, XF86Paste

: Paste from _clipboard_



shift+insert

: Paste from the _primary selection_



ctrl+shift+r

: Start a scrollback search



ctrl++, ctrl+=

: Increase font size by 0,5pt



ctrl+-

: Decrease font size by 0,5pt



ctrl+0

: Reset font size



ctrl+shift+n

: Spawn a new terminal. If the shell has been [configured to emit the

  OSC 7 escape

  sequence](https://codeberg.org/dnkl/foot/wiki#user-content-spawning-new-terminal-instances-in-the-current-working-directory),

  the new terminal will start in the current working directory.



ctrl+shift+o

: Enter URL mode, where all currently visible URLs are tagged with a

  jump label with a key sequence that will open the URL.



ctrl+shift+u

: Enter Unicode input mode.



ctrl+shift+z

: Jump to the previous, currently not visible, prompt. Requires [shell

  integration](https://codeberg.org/dnkl/foot/wiki#user-content-jumping-between-prompts).



ctrl+shift+x

: Jump to the next prompt. Requires [shell

  integration](https://codeberg.org/dnkl/foot/wiki#user-content-jumping-between-prompts).



#### Scrollback search



ctrl+r

: Search _backward_ for next match



ctrl+s

: Search _forward_ for next match



ctrl+w

: Extend current selection (and thus the search criteria) to the end

  of the word, or the next word if currently at a word separating

  character.



ctrl+shift+w

: Same as ctrl+w, except that the only word

  separating characters are whitespace characters.



ctrl+v, ctrl+shift+v, ctrl+y, XF86Paste

: Paste from clipboard into the search buffer.



shift+insert

: Paste from primary selection into the search buffer.



escape, ctrl+g

: Cancel the search



return

: Finish the search and copy the current match to the primary

  selection



### URL mode



t

: Toggle whether the URL is displayed in the jump label or not



escape, ctrl+c, ctrl+g, ctrl+d

: Exit URL mode without launching any URLs



### Mouse



left - **single-click**

: Drag to select; when released, the selected text is copied to the

  _primary_ selection. This feature is **disabled** when client has

  enabled _mouse tracking_.

: Holding shift enables selection in mouse tracking enabled

  clients.

: Holding ctrl will create a block selection.



left - **double-click**

: Selects the _word_ (separated by spaces, period, comma, parenthesis

  etc) under the pointer. Hold ctrl to select everything

  under the pointer up to, and until, the next space characters.



left - **triple-click**

: Selects the entire row



middle

: Paste from _primary_ selection



right

: Extend current selection. Clicking immediately extends the

  selection, while hold-and-drag allows you to interactively resize

  the selection.



wheel

: Scroll up/down in history



### Touchscreen



tap

: Emulates mouse left button click.



drag

: Scrolls up/down in history.

: Holding for a while before dragging (time delay can be configured)

  emulates mouse dragging with left button held.



## Server (daemon) mode



When run normally, **foot** is a single-window application; if you

want another window, start another foot process.



However, foot can also be run in a _server_ mode. In this mode, one

process hosts multiple windows. All Wayland communication, VT parsing

and rendering is done in the server process.



New windows are opened by running `footclient`, which remains running

until the terminal window is closed, at which point it exits with the

exit value of the client process (typically the shell).



The point of this mode is **a)** reduced memory footprint - all

terminal windows will share fonts and glyph cache, and **b)** reduced

startup time - loading fonts and populating the glyph cache takes

time, but in server mode it only happens once.



The downside is a performance penalty; all windows' input and output

are multiplexed in the same thread (but each window will have its own

set of rendering threads). This means that if one window is very busy

with, for example, producing output, then other windows will suffer.



And of course, should the server process crash, **all** windows will

be gone.



Typical usage would be to start the server process (`foot --server`)

when starting your Wayland compositor (i.e. logging in to your

desktop), and then run `footclient` instead of `foot` whenever you

want to launch a new terminal.



Foot support socket activation, which means `foot --server` will only be

started the first time you'll run `footclient`. (systemd user units are

included, but it can work with other supervision suites).



## URLs



Foot supports URL detection. But, unlike many other terminal

emulators, where URLs are highlighted when they are hovered and opened

by clicking on them, foot uses a keyboard driven approach.



Pressing ctrl+shift+o enters _"URL

mode"_, where all currently visible URLs are underlined, and is

associated with a _"jump-label"_. The jump-label indicates the _key

sequence_ (e.g. **"AF"**) to use to activate the URL.



The key binding can, of course, be customized, like all other key

bindings in foot. See `show-urls-launch` and `show-urls-copy` in the

`foot.ini` man page.



`show-urls-launch` by default opens the URL with `xdg-open`. This can

be changed with the `url-launch` option.



`show-urls-copy` is an alternative to `show-urls-launch`, that changes

what activating a URL _does_; instead of opening it, it copies it to

the clipboard. It is unbound by default.



Jump label colors, the URL underline color, and the letters used in

the jump label key sequences can be configured.



## Shell integration



### Current working directory



New foot terminal instances (bound to

ctrl+shift+n by default) will open in

the current working directory, **if** the shell in the "parent"

terminal reports directory changes.



This is done with the OSC-7 escape sequence. Most shells can be

scripted to do this, if they do not support it natively. See the

[wiki](https://codeberg.org/dnkl/foot/wiki#user-content-spawning-new-terminal-instances-in-the-current-working-directory)

for details.



### Jumping between prompts



Foot can move the current viewport to focus prompts of already

executed commands (bound to

ctrl+shift+z/x by

default).



For this to work, the shell needs to emit an OSC-133;A

(`\E]133;A\E\\`) sequence before each prompt.



In zsh, one way to do this is to add a `precmd` hook:



```zsh

precmd() {

    print -Pn "\e]133;A\e\\"

}

```



See the

[wiki](https://codeberg.org/dnkl/foot/wiki#user-content-jumping-between-prompts)

for details, and examples for other shells.



### Piping last command's output



The key binding `pipe-command-output` can pipe the last command's

output to an application of your choice (similar to the other `pipe-*`

key bindings):



```ini

[key-bindings]

pipe-command-output=[sh -c "f=$(mktemp); cat - > $f; footclient emacsclient -nw $f; rm $f"] Control+Shift+g

```



When pressing ctrl+shift+g, the last

command's output is written to a temporary file, then an emacsclient

is started in a new footclient instance. The temporary file is removed

after the footclient instance has closed.



For this to work, the shell must emit an OSC-133;C (`\E]133;C\E\\`)

sequence before command output starts, and an OSC-133;D

(`\E]133;D\E\\`) when the command output ends.



In fish, one way to do this is to add `preexec` and `postexec` hooks:



```fish

function foot_cmd_start --on-event fish_preexec

  echo -en "\e]133;C\e\\"

end



function foot_cmd_end --on-event fish_postexec

  echo -en "\e]133;D\e\\"

end

```



See the

[wiki](https://codeberg.org/dnkl/foot/wiki#user-content-piping-last-command-s-output)

for details, and examples for other shells



## Alt/meta



By default, foot prefixes _Meta characters_ with ESC. This corresponds

to XTerm's `metaSendsEscape` option set to `true`.



This can be disabled programmatically with `\E[?1036l` (and enabled

again with `\E[?1036h`).



When disabled, foot will instead set the 8:th bit of meta character

and then UTF-8 encode it. This corresponds to XTerm's `eightBitMeta`

option set to `true`.



This can also be disabled programmatically with `rmm` (_reset meta

mode_, `\E[?1034l`), and enabled again with `smm` (_set meta mode_,

`\E[?1034h`).



## Backspace



Foot transmits DEL (`^?`) on backspace. This corresponds to

XTerm's `backarrowKey` option set to `false`, and to DECBKM being

_reset_.



To instead transmit BS (`^H`), press

ctrl+backspace.



Note that foot does **not** implement DECBKM, and that the behavior

described above **cannot** be changed.



Finally, pressing alt will prefix the transmitted byte with

ESC.



## Keypad



By default, Num Lock overrides the run-time configuration

keypad mode; when active, the keypad is always considered to be in

_numerical_ mode. This corresponds to XTerm's `numLock` option set to

`true`.



In this mode, the keypad keys always sends either numbers (Num

Lock is **active**) or cursor movement keys (Up,

Down, Left, Right, Page

Up, Page Down etc).



This can be disabled programmatically with `\E[?1035l` (and enabled

again with `\E[?1035h`).



When disabled, the keypad sends custom escape sequences instead of

numbers, when in _application_ mode.



## DPI and font size



Font sizes are apparently a complex thing. Many applications use a

fixed DPI of 96. They may also multiply it with the monitor's scale

factor.



This results in fonts with different **physical** sizes (i.e. if

measured by a ruler) when rendered on screens with different DPI

values. Even if the configured font size is the same.



This is not how it is meant to be. Fonts are measured in _point sizes_

**for a reason**; a given point size should have the same height on

all mediums, be it printers or monitors, regardless of their DPI.



That said, on Wayland, Hi-DPI monitors are typically handled by

configuring a _"scaling factor"_ in the compositor. This is usually

expressed as either a rational value (e.g. _1.5_), or as a percentage

(e.g. _150%_), by which all fonts and window sizes are supposed to be

multiplied.



For this reason, and because of the new _fractional scaling_ protocol

(see below for details), and because this is how Wayland applications

are expected to behave, foot >= 1.15 will default to scaling fonts

using the compositor's scaling factor, and **not** the monitor

DPI.



This means the (assuming the monitors are at the same viewing

distance) the font size will appear to change when you move the foot

window across different monitors, **unless** you have configured the

monitors' scaling factors correctly in the compositor.



This can be changed by setting the `dpi-aware` option to `yes` in

`foot.ini`. When enabled, fonts will **not** be sized using the

scaling factor, but will instead be sized using the monitor's

DPI. When the foot window is moved across monitors, the font size is

updated for the current monitor's DPI.



This means that, assuming the monitors are **at the same viewing

distance**, the font size will appear to be the same, at all times.



_Note_: if you configure **pixelsize**, rather than **size**, then DPI

changes will **not** change the font size. Pixels are always pixels.



### Fractional scaling on Wayland



For a long time, there was no **true** support for _fractional

scaling_. That is, values like 1.5 (150%), 1.8 (180%) etc, only

integer values, like 2 (200%).



Compositors that _did_ support fractional scaling did so using a hack;

all applications were told to scale to 200%, and then the compositor

would down-scale the rendered image to e.g. 150%. This works OK for

everything **except fonts**, which ended up blurry.



With _wayland-protocols 1.32_, a new protocol was introduced, that

allows compositors to tell applications the _actual_ scaling

factor. Applications can then scale the image using a _viewport_

object, instead of setting a scale factor on the raw pixel buffer.



## Supported OSCs



OSC, _Operating System Command_, are escape sequences that interacts

with the terminal emulator itself. Foot implements the following OSCs:



* `OSC 0` - change window icon + title (but only title is actually

  supported)

* `OSC 2` - change window title

* `OSC 4` - change color palette

* `OSC 7` - report CWD (see [shell integration](#shell-integration))

* `OSC 8` - hyperlink

* `OSC 9` - desktop notification

* `OSC 10` - change (default) foreground color

* `OSC 11` - change (default) background color

* `OSC 12` - change cursor color

* `OSC 17` - change highlight (selection) background color

* `OSC 19` - change highlight (selection) foreground color

* `OSC 22` - set the xcursor (mouse) pointer

* `OSC 52` - copy/paste clipboard data

* `OSC 104` - reset color palette

* `OSC 110` - reset default foreground color

* `OSC 111` - reset default background color

* `OSC 112` - reset cursor color

* `OSC 117` - reset highlight background color

* `OSC 119` - reset highlight foreground color

* `OSC 133` - [shell integration](#shell-integration)

* `OSC 176` - set app ID

* `OSC 555` - flash screen (**foot specific**)

* `OSC 777` - desktop notification (only the `;notify` sub-command of

  OSC 777 is supported.)



See the **foot-ctlseq**(7) man page for a complete list of supported

control sequences.



## Programmatically checking if running in foot



Foot does **not** set any environment variables that can be used to

identify foot (reading `TERM` is not reliable since the user may have

chosen to use a different terminfo).



You can instead use the escape sequences to read the _Secondary_ and

_Tertiary Device Attributes_ (secondary/tertiary DA, for short).



The tertiary DA response is always `\EP!|464f4f54\E\\`, where

`464f4f54` is `FOOT` in hex.



The secondary DA response is `\E[>1;XXYYZZ;0c`, where `XXYYZZ` is

foot's major, minor and patch version numbers, in decimal, using two

digits for each number. For example, foot-1.4.2 would respond with

`\E[>1;010402;0c`.



**Note**: not all terminal emulators implement tertiary DA. Most

implement secondary DA, but not all. All _should_ however implement

_Primary DA_.



Thus, a safe way to query the terminal is to request the tertiary,

secondary and primary DA all at once, in that order. All terminals

should ignore escape sequences they do not recognize. You will have to

parse the response (which in foot will consist of all three DA

responses, all at once) to determine which requests the terminal

emulator actually responded to.



Starting with version 1.7.0, foot also implements `XTVERSION`, to

which it will reply with `\EP>|foot(version)\E\\`. Version is

e.g. "1.8.2" for a regular release, or "1.8.2-36-g7db8e06f" for a git

build.



# XTGETTCAP



`XTGETTCAP` is an escape sequence initially introduced by XTerm, and

also implemented (and extended, to some degree) by Kitty.



It allows querying the terminal for terminfo

capabilities. Applications using this feature do not need to use the

classic, file-based, terminfo definition. For example, if all

applications used this feature, you would no longer have to install

foot's terminfo on remote hosts you SSH into.



XTerm's implementation (as of XTerm-370) only supports querying key

(as in keyboard keys) capabilities, and three custom capabilities:



* `TN` - terminal name

* `Co` - number of colors (alias for the `colors` capability)

* `RGB` - number of bits per color channel (different semantics from

  the `RGB` capability in file-based terminfo definitions!).



Kitty has extended this, and also supports querying all integer and

string capabilities.



Foot supports this, and extends it even further, to also include

boolean capabilities. This means foot's entire terminfo can be queried

via `XTGETTCAP`.



Note that both Kitty and foot handles **responses** to

multi-capability queries slightly differently, compared to XTerm.



XTerm will send a single DCS reply, with `;`-separated

capability/value pairs. There are a couple of issues with this:



* The success/fail flag in the beginning of the response is always `1`

  (success), unless the very **first** queried capability is invalid.

* XTerm will not respond **at all** to an invalid capability, unless

  it's the first one in the `XTGETTCAP` query.

* XTerm will end the response at the first invalid capability.



In other words, if you send a large multi-capability query, you will

only get responses up to, but not including, the first invalid

capability. All subsequent capabilities will be dropped.



Kitty and foot on the other hand, send one DCS response for **each**

capability in the multi query. This allows us to send a proper

success/fail flag for each queried capability. Responses for **all**

queried capabilities are **always** sent. No queries are ever dropped.



# Credits



* [Ordoviz](https://codeberg.org/Ordoviz), for designing and

contributing foot's [logo](icons/hicolor/48x48/apps/foot.png).



# Bugs



Please report bugs to https://codeberg.org/dnkl/foot/issues



Before you open a new issue, please search existing bug reports, both

open **and** closed ones. Chances are someone else has already

reported the same issue.



The report should contain the following:



- Foot version (`foot --version`).

- Log output from foot (run `foot -d info` from another terminal).

- Which Wayland compositor (and version) you are running.

- If reporting a crash, please try to provide a `bt full` backtrace

  with symbols.

- Steps to reproduce. The more details the better.



# Contact



## IRC



Ask questions, hang out, sing praise or just say hi in the `#foot`

channel on [irc.libera.chat](https://libera.chat). Logs are available

at https://libera.irclog.whitequark.org/foot.



## Mastodon



Every now and then I post foot related updates on

[@[email protected]](https://linuxrocks.online/@dnkl)



# Sponsoring/donations



* GitHub Sponsors: https://github.com/sponsors/dnkl



# License



Foot is released under the [MIT license](LICENSE).